1. Field of the Invention
The present invention relates to a honeycomb structure.
2. Description of the Related Art
Conventionally, a SCR (Selective Catalytic Reduction) system which reduces NOx to nitrogen and water by using ammonia is known as one of systems for cleaning exhaust gas from an automobile (see the followings).4NO+4NH3+O2→4N2+6H2O6NO2+8NH3→7N2+12H2ONO+NO2+2NH3→2N2+3H2O
Also, zeolite is known as materials for adsorbing ammonia in a SCR system.
Meanwhile, International Publication No. WO 06/137149 discloses a honeycomb structure wherein a honeycomb unit is configured to include an inorganic particle and an inorganic fiber and/or whisker and the inorganic particle is at least one kind selected from the group including alumina, silica, zirconia, titania, ceria, mullite, and zeolites.
The entire content of International Publication No. WO 06/137149 is hereby incorporated by reference.